Synthesis, characterization and solid-phase C-13 NMR of naphtho-9-crown-3

The synthesis and characterization of naptho-9-crown-3, N9C3, as a novel 9- membered ring crown ether with greater lipophilicity than that of benzo-9-c rown-3, B9C3, is reported. The solution AA'BB' pattern of -CH2O- protons in N9C3 is close to that of B9C3. The solid-phase C-13 CPMAS NMR, as a tool f or conformation prediction, reveals that the solid-phase conformation of th e 9-membered ring crown cavity in N9C3 is different from B9C3, the two key C2O2CH(2) and C3O1CH(2) units are predicted to be out of naphthalene plane, and the two C1C2O2CH(2) and C4C3O1CH(2) torsion angles are close to each o ther. (C) 2000 Elsevier Science B.V. All rights reserved.